Excavation, mining, or other earth removal activities often employ machines, such as load-haul-dump machines (LHDs), wheel loaders, carry dozers, etc. to remove (i.e. scoop up) material from a pile at a first location (e.g., within a mine tunnel), to haul the material to a second location (e.g., to a crusher), and to dump the material at the second location. Productivity of the material removal process depends on the efficiency of a machine during each excavation cycle. For example, the efficiency increases when the machine can sufficiently load a machine tool (e.g., a bucket) with material at the pile within a short amount of time, haul the material via a direct path to the second location, and dump the material at the second location as quickly as possible.
Some applications require operation of the machines under hazardous working conditions. In these applications, an operator or an automated system may remotely control some or all of the machines to complete the material removal process. The remote operator or automated system, however, may not adequately determine a degree of tool engagement with the pile during loading of material from the pile. For example, the hardness or softness of the material in the pile can affect an amount of penetration of the tool into the pile. As a result, the tool may be under-loaded during a particular loading segment, and too much energy and time may be consumed by attempting to increase loading of the tool.
U.S. Pat. No. 7,555,855 of Alshaer et al. that issued on Jul. 7, 2009 (“the '855 patent”) discloses an automatic loading control system for loading a work implement of a machine with material from a pile. In particular, the '855 patent discloses a loading control system that controls the drive torque between the wheels and the ground to account for the toughness of the material pile. The '855 patent also discloses that the loading control system detects a speed of the machine and detects lift and tilt velocities of the lift and tilt actuators, respectively, associated with the work implement. The '855 patent further discloses controlling the drive torque between the wheels and the ground based on at least one of the lift velocity of the lift actuator, the tilt velocity of the tilt actuator, or the speed of the machine. By controlling the drive torque in this manner, the loading control system of the '855 patent aims to apply and maintain an adequate amount of force on the material pile to improve efficiency of the digging and loading process.
Although the loading control system disclosed in the '855 patent discloses controlling an amount of drive torque to apply adequate horizontal force on the material pile to allow the work implement to penetrate the material pile, the disclosed system may nonetheless be improved upon. In particular, although the disclosed system of the '855 patent may help the work implement to penetrate the pile horizontally, the disclosed system may not be able to ensure that the work implement is sufficiently loaded with material in each excavation cycle.
The excavation system of the present disclosure solves one or more of the problems set forth above and/or other problems of the prior art.